Driving journal compound



' Jan. 21, 1941- c. BRUNSTRUM ET AL 2,229,041

DRIVING JOURNL COMPOUND Filed Sept. 29, 1958 imatented Jan. 2l, i941tiNVi'E STATES rant DRIVING JOURNAL U@ i lili" of Indiana ApplicationSeptember 29, 1933, Serial No. 232,305

6 Claims.

This invention relates to lubricants of the driving journal compoundtype and particularly to such lubricants in which part of the soapcontent is sodium laurate.

Lubricants of the driving journal compound type consist wholly orlargely of soda soap and lubricating oil, the soda soap comprising fromabout 35% to about 55% and Preferably from about 40% to about 50% of theproduct. The soap content of such products should be made from fattyacids rather than fats, i. e. should be substantially glycerine free,and should also be substantially anhydrous although a trace of water isusually present.

In the past, lubricants of the driving journal compound type have beenmade using soda soaps of fatty acid materials consisting almost whollyof fatty acids having at least i6 carbon atoms per molecule, forinstance palmitic acid (C15H31COOH),stearic acid (CuHai-)COOl-l) orbehenic acid (Carl-14300011). One type of fatty acid which has beenfound highly desirable in the manufacture of lubricants of the drivingjournal compound type is that made up of fatty p acids split fromhydrogenated fats. These fatty acids as Well as those which arehydrogenated after being split from the natural fats are referred tc ashydrogenated fatty acids. Hydrogenated fish oil fatty acids areparticularly suitable.

We find, however, that for the most part the use of these hydrogenatedfatty acids or the use of other fatty acids made up predominantly ofcompounds having at least 16 carbon atoms per ,molecule are deficient inone very important' property known as softening time. We have found thatsmall amounts of lauric acid (CnHzaCOOH) added to the conventional fattyacids result in the production of a driving journal compound of greatlyincreased softening time and also improved structure and pressability.

It is an object of our invention to provide new and improved lubricantsof `the driving journal compound type and methods of manufacturetherefor. Another object of our invention is to provide lubricants ofthe driving journal compound type having good body and high plasticityat room temperature coupled with very high softening times at elevatedtemperatures?. It is also an object of our invention to make possiblethe manufacture of high quality lubricants of the driving journalcompound type from fatty acid materials which could not heretofore beused in.

the manufacture of such quality lubricants. A further object of ourinvention is to provide lubricants of the driving journal compound typehaving improved pressing characteristics. Another making lubricants ofthe driving journal compound type under steam lrettle conditions whichhave properties even more advantageous than those of products whichcould be made hereto fore only under the more drastic conditions of thefire kettle technique. Other and more detailed objects, advantages and-uses of our invention will become apparent as the description thereofproceeds.

It is highly desirable that a lubricant of the driving journal compoundtype be plastic at ordinary temperatures so that it can be pressed intosticks or blocks and so that the formed lubricant will not break underconditions of use. At the same time it is very desirable that suchlubricants retain their body at elevated temperatures so that they willcontinue to resist flow under low pressures. Otherwise these lubricantsdo not retain their form during use and are consumed too rapidly.

,We nd that these properties can be combined to a most unusual degree bythe use of a relatively small amount of lauric acid along with a majoramount of conventional fatty acids, preferably hydrogenated fatty acids.

Softening time is an index of quality from the service standpoint and ismeasured by a test in which a cylinder of driving journal compound 1A;inch in diameter and about 5/8 inch long is heated on an oil or mercurybath to the desired test ternperature While subjected to the weight ofan 85 gram cylinder which provides a pressure on the driving journalcompound comparable to the pressure to which the compound is subjectedin actual operation when it is forced by a spring against a hot bearing.softening time is dened as the time required 4to flatten the testcylinder 1/4 inch under these conditions.

As illustrating the effect of a small amount of lauric acid on softeningtime, a driving journal compound containing 45% sodium hydrogenated`fish oil soap, 45% of steam refined oil having a 530 F. flash point and10% of heavy black oil has a softening time of about 1500 seconds, whileif only of the hydrogenated fish oil fatty acids is replaced with lauricacid (90% pure), the softening time increases to 8000 seconds while with20% vlauric acid in the total fatty acids the softening `time becomes16,000 seconds. f

It is thus apparent that an extremely small amount of lauric acid givesan exceptionally ne product and permits the use of other fatty acidmaterials which are completely unsuitable without the added lauric acid.At the same time the lauric acid improves the structure of the drivingjournal compound at ordinary temperatures and also improves thepressability of the product.

The accompanying drawing, which is a graph of a function of softeningtime against the composition of the fatty acids used in a drivingjournal compound illustrates the effect of using various proportions of90% pure lauric acid and a commercial hydrogenated fish oil fatty acidmaterial known as Hardesty fatty acids. In this graph the ordinatemeasures the distance which the test cylinder of driving journalcompound moves in 2000 seconds at the test temperature of 260 F., whilethe abscissa measures the composition of the fatty acid component of thedriving journal compound. Thus with pure lauric acid there issubstantially no flattening of the test cylinder of driving journalcompound under these time and ternperature conditions and very littleflattening when 25% of lauric acid is used along with 75% of thehydrogenated sh oil fatty acids. On the other hand, when less than thisamount of lauric acid is used, the amount of flattening increases veryrapidly. When no lauric acid is used the flattening occurs long beforethe expiration of 2000 seconds at 260 F., i. e. the softening time isless than 2000 seconds, in fact about 1500 lseconds.

The preferred source of lauric acid for use in accordance with ourinvention is the relatively pure material obtained by the fractionaldistillation of various types of fatty acids from natural sources. Weprefer to add the lauric acid in the form of a highly concentratedmaterial, say 75% pure or better, but fatty acid material containing aslittle as 40% lauric acid can be used, in quantities suflicient to giveamounts of added lauric acid within the range from about 3% to about 25%of the total fatty acids used.

Lubricants in accordance with my invention can be made using any of theprocedures known in the art by merely substituting the fatty acidmixtures above described for those heretofore used. However, these fattyacid mixtures can be used particularly advantageously in a steam kettletype of operation as contrasted with re kettle technique and while fattyacids heretofore used give low softening time products when steamkettles are used this is not true when low molecular Weight fatty acidsare used. The data above given are for driving journal compounds made ina steam kettle type of operation.

In the steam kettle'technique the soap is formed in at least a portion,preferably all, of the oil at a temperature of from about 260 F. toabout 300 F. In no case should the grease be heated above 330 F.

While we have described our invention in connection with certainpreferred embodiments thereof, it is to be understood that these are byway of illustration and not by way of limitation and we do not mean tobe bound thereby but only to the scope of the appended claims.

We claim:

l. A lubricant of the driving journal compound type comprising soda soapmade from a major quantity of hydrogenated fatty acids to which fromabout 3% to about 25% of lauric acid has been added.

2. In a substantially anhydrous lubricant containing from about 35% toabout 55% soda soap, at least the bulk of the remainder beinglubricating oil, the improvement which consists in using soda soap madefrom a major quantity of hydrogenated fatty acids of predominantly atleast 16 carbon atoms per molecule together with from about 3% to about25% of added lauric acid.

3. In the manufacture of a lubricant of the driving journal compoundtype the step which comprises saponifying a major amount of a fatty acidmaterial made up largely of compounds having at least 16 carbon atomsper molecule and a minor proportion of a fatty acid material containingat least about 40% lauric acid, said lastmentioned fatty acid materialbeing used in quantities suicient to bring the amount of added lauricacid within the range from about 3% to about 25% of the total fattyacids used.

4. In the manufacture of a lubricant of the driving journal compoundtype the step which comprises saponifying a major amount of ahydrogenated fatty acid material made up largely of compounds having atleast 16 carbon atoms per molecule and a minor proportion of a fattyacid material containing at least about 75% lauric acid, saidlast-mentioned fatty acid material being used in quantities sufficientto bring the amount of added lauric acid Within the range from about 3%to about 25% of the total fatty acids used.

.5. A step according to claim 4 in which said hydrogenated fatty acidmaterial is hydrogenated sh oil fatty acids normally yielding a drivingjournal compound of poor softening time.

6. In the manufacture of a lubricant of the driving journal compoundtype the step which comprises saponifying fatty acids in at least aportion of the lubricating oil at a temperature from about 260 F. toabout 300 F., said fatty acids containing from about 3% to about 25% ofadded lauric acid, the remainder being made up of fatty acids containingpredominantly at least 16 carbon atoms per molecule.

LAWRENCE C. BRUNSTRUM. EIMER W. ADAMS.

